2010 Prius Upgraded Hybrid Battery Question for technical help

Discussion in 'Gen 3 Prius Technical Discussion' started by spgview211, Dec 7, 2025.

  1. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    I purchased a 2010 Prius, according to the previous owner the hybrid battery was changed at some point. I thought cell/modules were original ,until I removed the battery and put eyes on it. Unsure if
    The car remained parked for a long time and discharge due to non use.

    I plan to recharge or rebuild and balance the pack after determining which module is bad. I want to charge and discharge 3 times and record the mah on each cell. I purchased a Tenergy T180 charger to help.

    Discovered the cells are cylindrical in shape and green and 14 total. Each section say 6.5AH and has 4.4V stamped with “Electron electric vehicle experts.” Appear to be 3 rows tall in each module.

    I’m trying to figure out the following:
    1. What voltage to charge each individual module? And how many Amps? I read online it might be 14.4V but want to confirm nothing indicate on the battery. Other than 4.4v and 6.5ah

    2. What amp to discharge and to what voltage to not damage the cell/module?

    I’m including pictures of the current voltage after being removed without charged.
    I just realized I labeled them backwards 1 should be closed to the fan.
     
  2. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    +photos
     

    Attached Files:

  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    114,142
    52,025
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    PriusCamper and indel like this.
  4. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    Thanks for the response. All of these video work with stock cells(28) per pack.

    I have updated cylindrical cells that are 14.4V and consist of (14) total with higher voltage in each.

    similar to this upgrade.



    Cannot seem to find a video of a rebuild or any post outlining reconditioning. Here’s a photo of the pack - all help is appreciated .
    Do I charge to 17.0v-18.0v @ 6500 MAH .8 amp?
    Discharge at 1 amp to 12.5V ?
     

    Attached Files:

    bisco likes this.
  5. indel

    indel Member

    Joined:
    Apr 1, 2024
    151
    54
    1
    Location:
    Northwest Indiana
    Vehicle:
    2012 Prius
    Model:
    Two
    @spgview211 I recommend doing a consultation with @ericbecky. He has a ton of experience with hybrid batteries.
     
  6. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    Appreciate the insight, I’ll tag him and see if he can offer pointers. I looked him and he’s on the East coast.
    I set my charger to .8 amps and it charged to apx 17.0 V @ ~2500 mah before timing out (200min safety). I increased to 2.0amps @ 600 minute safety cut-out.
    @ericbecky

    Quick question: Do I set my charger to 6500mah or higher to 8500mah? I plan to discharge at 1.0amp (or higher based on feedback) to try and recondition these cells and figure out which one is bad before rebalancing/ rebuilding.
     
  7. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,713
    1,927
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    IMHO; your best bet is to try to find OE markings on the battery modules and do a search for their specifications. There were several iteration of after market cylindrical battery systems made, so the only way to get accurate specs. is to contact the seller of that pack - if they're still around. I personally wouldn't consider a cylindrical module pack to be an upgrade when compared to Toyota's track record of their traction packs.
    The worse news is that you have an INVALID traction battery core, if you decide to buy a new one from Toyota. Toyota won't accept it, so you'll also lose your core charge in that transaction.
    FWIW; the gen1 Honda Civic Hybrids used cylindrical modules too; I got about 70K miles before it needed replacement - luckily still covered under warranty due to CARB rules.

    Good Luck.....
     
  8. DirkAshburn

    DirkAshburn Member

    Joined:
    Apr 6, 2020
    151
    63
    1
    Location:
    Virginia
    Vehicle:
    2011 Prius
    Model:
    Four
  9. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    Thank you. Might have been a downgrade, based on the chemist
    It appears I found 14.4V 6.5ah ,
     

    Attached Files:

  10. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    Tempted to go the used route with a JDM battery and buy the Prolong battery charger to fully charge or balance the pack prior to install, if I can’t get this functional in a week or two.

    OEM more than likely has better chemistry than these cells, to your point maybe it’s a downgrade and not an upgrade….
     
  11. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    12,819
    5,198
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    JDM wouldn't be wise when battery cores can be had for only $200... And if you want to have a rebuilt pack on the shelf and one in the car that could work, but its a steep learning curve to rebuild packs well and with each rebuild it becomes less viable. Even the best rebuilders can onlymake money on 3-year warranties. Of course if you get good at finding packs for cheap and enjoy the rebuilding process you can make money helping out friends and family.

    I ended up with lots of spare OEM packs thanks to being an installer of Sodium-Ion packs... I usually sell them to rebuilders but always have a spare lying around.

    As with all things, the more involved you get with stuff like this, the more opportunities arise at a great price. But if you have a spare couple thousand bucks, just get something new and forget about it and don't bother with rebuild learnings.
     
  12. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    @PriusCamper @BiomedO1
    I’m still trying to piece this together and appreciate the insight and help.

    Literally, bought it disassembled and in pieces. A few weeks of charging all cells, and got it running finally with traction lights,abs, red triangle;unsure if traction pack is working entirely. And have more test to run in Dr. Prius- all lights went away after a drive and obd II reset except P0A0D.

    Initially had codes P03BD,U029A; cleared these and drove it more and now triggered P0A0D. Reset it again.

    Checked the “Main safety battery Interlock Disconnect” and the lever was engaged to the right as others suggested this would trigger that specific code. Watched a video of removal, and noticed under the disconnect there is a 2 pin wire below the interlock. It’s also connected.
    Any other ideas to check in case it reappears?
     

    Attached Files:

    #12 spgview211, Jan 1, 2026 at 2:06 AM
    Last edited: Jan 1, 2026 at 2:25 AM
  13. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    2,268
    898
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    If you have an active/current P0A0D code, you would not be able to start the car. Maybe the code is historical? What scanner or app are you using to read codes.
     
  14. indel

    indel Member

    Joined:
    Apr 1, 2024
    151
    54
    1
    Location:
    Northwest Indiana
    Vehicle:
    2012 Prius
    Model:
    Two
    Where can one get battery cores for $200? I would get one, if for nothing else than to learn to refurbish and balance.
     
  15. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    it could’ve been now that I think about it, I was using the Dr. Prius app and a Launch X431. Will drive today and see
     
  16. spgview211

    spgview211 New Member

    Joined:
    Dec 7, 2025
    9
    1
    0
    Location:
    Bay Area,Ca
    Vehicle:
    2010 Prius
    Model:
    Four
    @Brian1954
    Do you by chance know where cores are available to rebuild at this price ?
     
  17. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    2,268
    898
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    I do not know, but @PriusCamper can answer that question since he made the claim.